Compounds of the anthraquinone series and process for producing the same



Patented Jan. 19, 1937 UNITED STATES COMPOUNDS OF THE ANTHRAQUINONESERIES AND PROCESS FOR PRODUCING THE SAME ,William Dettwyler, Milwaukee,Wis., assignor to E. I. du Pont de Nemours & Company, Wilmington, Del.,a corporation of Delaware No Drawing. Original application May 24, 1933,

Serial No. 672,641.

Divided and this application October 21, 1935, Serial No. 45,970

5. Claims.

This invention relates to the preparation of new and valuable compoundsof the anthraquinone series and more particularly to thepreparation ofdihalogen-tetra-acidylamino-1,1'-dianthraquinonyls. This application isa division of U. S. application Ser. No. 672,641, filed May 24, 1933.

It is an object of this invention to prepare new and useful dyestufiintermediates of the anthraquinone series which have been found to beparticularly useful in the preparation of fiavanthrone dithia'zoles,although their use is obviously not limited thereto.

According to the present invention, ana,a'-dihalogen-c,[3-diacylamino-anthraquinone, such as for example1,5,2,6- or 1,8,2,7-diha1ogen-diben zoylamino-anthraquinone is subjectedto condensation in the presence of a copper catalyst to produce thecorresponding dihalogen-tetrabenzoylamino. 1,1 dianthraquinonyl. Thiscompound, it has been found, may be subjected to simultaneous hydroylsisand ring closure to give the corresponding u,a'-dihalogen c,p'diaminoflavanthrone as more particularly described in the parentapplication above referred to.

Without limiting my invention to any particular procedure, the followingexamples are given to illustrate my specific mode of operation. Partsmentioned are by weight.

Step 1.-Rreparation of the initial material 750 parts of drynitrobenzene and parts of cake is washed with nitrobenzene and alcohol,and finally dried in the usual manner.

Step 2.Preparation of the first intermediate 800 parts of drynitrobenzene, parts of 1,5- dichloro 2,6 dibenzoyldiamino-anthraquinone, 40 parts of copper powder, and 2 parts of sodaash are heated together to reflux temperature and held at thistemperature about 20 hours. The color of the suspension changes fromyellow to olive. The mass is now cooled to- 20 C., and filtered. Thefilter cake is washed successively with nitrobenzene, alcohol, and hotwater. The wet cake is suspended in 1000 parts of water, 100 parts ofconcentrated sulfuric acid and 50 parts of common salt are added, andthe mass is warmed to 50 C. About 20 parts of sodium chlorate are thenadded gradually, until a distinct excess of chlorine is produced. Aftera further half hour at this temperature, the mass is filtered, and thefilter cake is washed free of acid and dried as usual. The product ismost probably '5,5-dichloro-2,6,2',6-tetrabenzoyl-tetramino 1,1dianthraquinonyl, of the formula:

In dry state it has the form of short olive needles, practicallyinsoluble in nitrobenzene, but I soluble in concentrated sulfuric acidwith a greenish-yellow color.

1,8-dichloro-2,7-diamino-anthaquinone may be used in place of1,5-dichloro-2,6-diamino-anthraquinone specifically mentioned in theabove example. Other acidylaminoanthraquinones such as the correspondingdiacetyl-diamino-anthraquinone compounds may be used in place of thedibenzoylamino-anthraquinones, for instance 1,5 dichloro-2,fi-diacetyldiamino-anthraquinone prepared in known manner from1,5-dichloro- 2,6-diamino-anthraquinone and acetic anhydride may besubjected to condensation to give the correspondingdichloro-tetraacetylamino-1,1-dianthraquinonyl.

It will be understood that many variations and modifications arepossible in my preferred procedure without departing from the spirit ofthis invention.

I claim:

1. The process which comprises heating ana,a-dihalogen-flfi-diacylamino-anthraquinone in which one halogen andone acylamino group are attached to each benzene nucleus of theanthraquinone molecule in ortho position to each other in an inertorganic medium and in the presence of a copper catalyst to producedihalogen-tetraacyl-tetramino-1,1-dianthraquinony1.

2. The process which comprises heating 1,5- dich1oro-2,6-dibenzoyldiamino anthraquinone

